Recording condition setting method, program, recording medium, and information recording apparatus

ABSTRACT

A recording condition setting method includes the steps of: a) obtaining identification information from an information recording medium; b) searching through a table including history information indicative of temperature information detected in the vicinity of a light source and corresponding optimum recording power; c) extracting history information corresponding to the identification information; d) detecting temperature information detected in the vicinity of the light source; e) acquiring an optimum recording power by referring to the temperature information detected in step d) and the history information extracted in step c); and f) setting the optimum recording power acquired in step e) as a recording condition.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a recording condition settingmethod, program, recording medium, and information recording apparatus.More particularly, the present invention relates to a recordingcondition setting method for setting a recording condition whenrecording information to an information recording apparatus, a programused for a recording apparatus, a recording medium having the programrecorded thereto, and a recording apparatus for recording information toa recording medium.

2. Description of the Related Art

Due to improvements made in the functions of personal computers inrecent years, the personal computer has become able to handleaudio-visual information such as music and images. Since audio-visualinformation contains a vast amount of data, optical disks such as CDs(Compact Disc), and DVDs (Digital Versatile Disc) have gained attentionfor use as information recording media. Furthermore, as the costs forsuch optical disks become lower, an optical disk apparatus has becomewidely employed as a personal computer peripheral serving as aninformation recording apparatus. The optical disk apparatus records anderases information by irradiating a fine spot of laser light to spiralor concentric tracks formed on a recording surface of an optical disk,and reproduces information according to the light reflected from therecording surface. The optical disk apparatus has an optical pickup unitarranged thereto for irradiating the laser light to the recordingsurface of the optical disk and also for receiving the light reflectedfrom the recording surface.

Typically, the optical pickup unit includes, for example, a light sourcefor irradiating a laser light of a prescribed irradiation power (outputpower), an optics system for guiding the laser light irradiated from thelight source to a recording surface of an information recording mediumand also for guiding the laser light reflected from the recordingsurface to a prescribed light receiving location, and a light receivingelement positioned at the light receiving location.

Information is recorded in the optical disk according to the lengths andcombination of marked areas (pits) and unmarked areas (space), whichhave different reflectivities. In recording the information in theoptical disk, the irradiation power of the light source is controlled sothat the marked areas and space areas may be formed at a prescribedlocation and thus with a prescribed length.

In a case of forming marked areas in a recordable type optical disk(hereinafter referred to as “dye type disk”) which contains organic dyein a recording layer thereof, (e.g. CD-R (CD-recordable) disk, DVD-R(DVD-recordable) disk), a laser light with an increased irradiationpower is applied to the dye type disk to heat and melt the dye, therebytransmuting or transforming a substrate portion contacting the area atwhich the laser light is applied. Meanwhile, in a case of forming spaceareas, the irradiation power of the laser light is reduced to a degreesubstantially equal to that during reproduction in order to prevent thesubstrate from transmuting and transforming. Therefore, the reflectivityof the marked areas is lower than that of the space areas.

Typically, the dye type disk exhibit significant changes in recordingsensitivity in correspondence to changes in the wavelength of laserlight. Therefore, changes in the wavelength of laser light will alsochange the optimum irradiation power when forming the marked areas(hereinafter referred to as “recording power”). Furthermore, changes inthe temperature of the light source will change the wavelength of thelaser light irradiated from the light source. That is, the optimumrecording power will change in correspondence to a change in thetemperature of the light source.

Accordingly, Japanese Laid-Open Patent Publication No.2001-297437(hereinafter referred to as “first conventional example”),for example, shows an optical recording apparatus having a temperaturesensor disposed near an optical pickup unit, in which the temperaturenear the optical pickup unit is detected by the temperature sensorduring a recording process. When the temperature surpasses a prescribedvalue, the optical recording apparatus performs a test-recordingprocedure for obtaining an optimum recording power, so-called OPC(Optimum Power Control) procedure.

In another example, Japanese Laid-Open Patent Publication No. 5-144061.(hereinafter referred to as “second conventional example”) shows anirradiation power control apparatus in which the apparatus obtains theoptimum recording power of a laser beam irradiated from a laser diode inaccordance with an identification code of an optical disk, relates thetemperature near the laser diode in correspondence to the obtainedoptimum recording power of the identification code, stores thetemperature information in a memory, and controls the irradiation powerof the laser diode according to the temperature information. Theirradiation power control apparatus reads the identification code of theoptical disk prior to recording in the optical disk, derives thetemperature information corresponding to the identification code fromthe memory, and performs the OPC procedure when the difference in thevalue between the derived temperature and the temperature detected froma sensor disposed near the laser diode surpasses a prescribed value, tothereby obtain the optimum recording power.

In another example, Japanese Patent Laid-Open Publication No.6-76288(hereinafter referred to as “third conventional example”) showsan optical disk apparatus in which the optical disk apparatus performs arunning OPC procedure to enable correction of recording power. Theoptical disk apparatus first performs a standard OPC procedure to obtainthe optimum recording power, and begins recording in accordance with theobtained optimum recording power. Subsequently, upon forming pits in anoptical disk, the optical disk apparatus detects the intensity of thelight reflected from the recording area and corrects the recording powerbased on the difference between a predetermined value and the value ofthe detected intensity.

Recordable type optical disks are formed with a test-recording area fordetermining optimum recording power. This area is called a “powercalibration area (PCA)”. For example, a CD-R has a PCA serving as atest-recording area divided into 100 partitions. Each of the partitionsof the test-recording area is formed of 15 frames. Typically, a singlepartition is used for test-recording prescribed data in an optical diskwhere the test-recording is performed with a certain linear speed andwhere recording power for each frame is changed step by step.Accordingly, among the recording power level for each of the frames, therecording power displaying the highest recording quality is chosen asthe optimum recording power. Nevertheless, since the optical recordingapparatus of the first conventional example and the irradiation powercontrol apparatus of the second conventional example both perform theOPC procedure whenever a value corresponding to temperature surpasses aprescribed value, both of the examples tend to face a problem of lackingthe recording area sufficient for required test-recording. Furthermore,since the optical recording apparatus of the third conventional examplealways performs the OPC procedure prior to a recording procedure, thethird example will also face the lack of sufficient test-recording areaafter repetitively recording small amounts of data.

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide a recordingcondition setting method, program, recording medium, and informationrecording apparatus that substantially obviate one or more of theproblems caused by the limitations and disadvantages of the related art.

Features and advantages of the present invention are set forth in thedescription that follows, and in part will become apparent from thedescription and the accompanying drawings, or may be learned by practiceof the invention according to the teachings provided in the description.Objects as well as other features and advantages of the presentinvention will be realized and attained by a recording condition settingmethod, program, recording medium, and information recording apparatusparticularly pointed out in the specification in such full, clear,concise, and exact terms as to enable a person having ordinary skill inthe art to practice the invention.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied and broadly described herein, theinvention provides a recording condition setting method, including thesteps of: a) obtaining identification information from an informationrecording medium; b) searching through a table including historyinformation indicative of temperature information detected in thevicinity of a light source and corresponding optimum recording power; c)extracting history information corresponding to the identificationinformation; d) detecting temperature information detected in thevicinity of the light source; e) acquiring an optimum recording power byreferring to the temperature information detected in step d) and thehistory information extracted in step c); and f) setting the optimumrecording power acquired in step e) as a recording condition.

It is to be noted that the term “temperature information” is not limitedto temperature itself, but may also include information changing incorrespondence to change of temperature, and information convertible totemperature.

The recording condition setting method of the present invention mayfurther include the steps of: g) determining whether the identificationinformation is recorded in the information recording medium; h) creatingnew identification information when the identification information isnot recorded in the information recording medium; and i) recording thenew identification information in the information recording medium.

In the recording condition setting method of the present invention, stepe) may further include a step of calculating with reference to thehistory information extracted in step c).

In the recording condition setting method of the present invention, thecalculation may be an approximate calculation or an interpolationcalculation.

The recording condition setting method of the present invention mayfurther include the steps of: j) setting an effective temperature rangeaccording to the history information extracted in step c); k)determining whether the temperature information detected in step d) isincluded in the effective temperature range; l) acquiring anotheroptimum recording power by test-recording in the information recordingmedium when the temperature information detected in step d) is notincluded in the effective temperature range; and m) setting the otheroptimum recording power as the recording condition.

The recording condition setting method of the present invention mayfurther include a step of: n) adding the other optimum recording powerto the table in correspondence with the temperature information detectedin step d) and the identification information.

Another recording condition setting method of the present inventionincludes the steps of: a) acquiring an optimum recording power andtemperature information corresponding to the optimum recording power; b)recording the optimum recording power and the temperature information ina memory; c) detecting temperature information of an informationrecording medium; d) determining whether the temperature information ofthe information recording medium matches the temperature informationrecorded in the memory; and e) setting an optimum recording power of theinformation recording medium as a recording condition when thetemperature information of the information recording medium matches thetemperature information recorded in the memory.

The recording condition setting method of the present invention mayfurther include the steps of: f) estimating another optimum recordingpower when the temperature information of the information recordingmedium does not match with any temperature information recorded in thememory; and g) setting the other optimum recording power as therecording condition.

In the recording condition setting method of the present invention, theother optimum recording power in step f) may be estimated by anapproximate calculation or an interpolation calculation with referenceto the optimum recording power and the temperature information recordedin the memory.

The recording condition setting method of the present invention mayfurther include a step of: h) adding the other optimum recording powerto the memory in correspondence with the temperature information of theinformation recording medium and identification information of theinformation recording medium.

A program of the present invention includes the steps of: a) obtainingidentification information from an information recording medium; b)searching through a table including history information indicative oftemperature information detected in the vicinity of a light source andcorresponding optimum recording power; c) extracting history informationcorresponding to the identification information; d) detectingtemperature information detected in the vicinity of the light source; e)acquiring an optimum recording power by referring to the temperatureinformation detected in step d) and the history information extracted instep c); and f) setting the optimum recording power acquired in step e)as a recording condition.

The program of the present invention may further include the steps of:g) determining whether the identification information is recorded in theinformation recording medium; h) creating new identification informationwhen the identification information is not recorded in the informationrecording medium; and i) recording the new identification information inthe information recording medium.

In the program of the present invention, step e) may further include astep of calculating with reference to the history information extractedin step c).

In the program of the present invention, the calculation may be anapproximate calculation or an interpolation calculation.

The program of the present invention may further include the steps of:j) setting an effective temperature range according to the historyinformation extracted in step c); k) determining whether the temperatureinformation detected in step d) is included in the effective temperaturerange; l) acquiring another optimum recording power by test-recording inthe information recording medium when the temperature informationdetected in step d) is not included in the effective temperature range;and m) setting the other optimum recording power as the recordingcondition.

The program of the present invention may further include a step of: n)adding the other optimum recording power to the table in correspondencewith the temperature information detected in step d) and theidentification information.

Another program of the present invention includes the steps of: a)acquiring an optimum recording power and temperature informationcorresponding to the optimum recording power; b) recording the optimumrecording power and the temperature information in a memory; c)detecting temperature information of an information recording medium; d)determining whether the temperature information of the informationrecording medium matches the temperature information recorded in thememory; and e) setting an optimum recording power of the informationrecording medium as a recording condition when the temperatureinformation of the information recording medium matches the temperatureinformation recorded in the memory.

The program of the present invention may further include the steps of:f) estimating another optimum recording power when the temperatureinformation of the information recording medium does not match with anytemperature information recorded in the memory; and g) setting the otheroptimum recording power as the recording condition.

In the program of the present invention, the other optimum recordingpower in step f) may be estimated by an approximate calculation or aninterpolation calculation with reference to the optimum recording powerand the temperature information recorded in the memory.

The program of the present invention may further include a step of: h)adding the other optimum recording power to the memory in correspondencewith the temperature information of the information recording medium andidentification information of the information recording medium.

A recording medium of the present invention has a program recordedthereto, in which the program includes the steps of: a) obtainingidentification information from an information recording medium; b)searching through a table including history information indicative oftemperature information detected in the vicinity of a light source andcorresponding optimum recording power; c) extracting history informationcorresponding to the identification information; d) detectingtemperature information detected in the vicinity of the light source; e)acquiring an optimum recording power by referring to the temperatureinformation detected in step d) and the history information extracted instep c); and f) setting the optimum recording power acquired in step e)as a recording condition.

In the recording medium of the present invention, the program recordedin the recording medium may further include the steps of: g) determiningwhether the identification information is recorded in the informationrecording medium; h) creating new identification information when theidentification information is not recorded in the information recordingmedium; and i) recording the new identification information in theinformation recording medium.

In the recording medium of the present invention, step e) may furtherinclude a step of calculating with reference to the history informationextracted in step c).

In the recording medium of the present invention, the calculation may bean approximate calculation or an interpolation calculation.

In the recording medium of the present invention, the program recordedin the recording medium may further include the steps of: j) setting aneffective temperature range according to the history informationextracted in step c); k) determining whether the temperature informationdetected in step d) is included in the effective temperature range; l)acquiring another optimum recording power by test-recording in theinformation recording medium when the temperature information detectedin step d) is not included in the effective temperature range; and m)setting the other optimum recording power as the recording condition.

In the recording medium of the present invention, the program recordedto the recording medium may further include a step of: n) adding theother optimum recording power to the table in correspondence with thetemperature information detected in step d) and the identificationinformation.

In another recording medium of the present invention having a programrecorded therein, the program recorded in the recording medium includesthe steps of: a) acquiring an optimum recording power and temperatureinformation corresponding to the optimum recording power; b) recordingthe optimum recording power and the temperature information in a memory;c) detecting temperature information of an information recording medium;d) determining whether the temperature information of the informationrecording medium matches the temperature information recorded in thememory; and e) setting an optimum recording power of the informationrecording medium as a recording condition when the temperatureinformation of the information recording medium matches the temperatureinformation recorded in the memory.

In the recording medium of the present invention, the program recordedin the recording medium may further include the steps of: f) estimatinganother optimum recording power when the temperature information of theinformation recording medium does not match with any temperatureinformation recorded in the memory; and g) setting the other optimumrecording power as the recording condition.

In the recording medium of the present invention, the other optimumrecording power in step f) may be estimated by an approximatecalculation or an interpolation calculation with reference to theoptimum recording power and the temperature information recorded in thememory.

In the recording medium of the present invention, the program recordedin the recording medium may further include a step of: h) adding theother optimum recording power to the memory in correspondence with thetemperature information of the information recording medium andidentification information of the information recording medium.

An information recording apparatus of the present invention includes: amemory unit storing a table including history information indicative oftemperature information detected in the vicinity of a light source andcorresponding optimum recording power; a detecting unit detectingtemperature information detected in the vicinity of the light source; anobtaining unit obtaining identification information from an informationrecording medium; an extracting unit extracting history informationcorresponding to the identification information by searching through thetable; a setting unit acquiring an optimum recording power by referringto the temperature information detected by the detecting unit and thehistory information extracted by the extracting unit, and setting theacquired optimum recording power as a recording condition; and arecording unit recording information in the information recording mediumaccording to the recording condition.

The information recording apparatus of the present invention may furtherinclude: a determining unit determining whether the identificationinformation is recorded in the information recording medium; anidentification information recording unit creating new identificationinformation when the identification information is not recorded in theinformation recording medium, and recording the new identificationinformation in the information recording medium.

In the information recording apparatus of the present invention, thesetting unit may acquire the optimum recording power by calculating withreference to the history information extracted by the extracting unit.

In the information recording apparatus of the present invention, thecalculation may be an approximate calculation or an interpolationcalculation.

The information recording apparatus of the present invention may furtherinclude: a temperature range setting unit setting an effectivetemperature range according to the history information extracted by theextracting unit; another determining unit determining whether thetemperature information detected by the detecting unit is included inthe effective temperature range; another setting unit acquiring anotheroptimum recording power by test-recording in the information recordingmedium when the temperature information detected by the detecting unitis not included in the effective temperature range, and setting theother optimum recording power as the recording condition.

In the information recording apparatus of the present invention, theother setting unit adds the other optimum recording power to the tablein correspondence with the temperature information detected by thedetecting unit and the identification information.

Another information recording apparatus of the present inventionincludes: an acquiring unit acquiring an optimum recording power andtemperature information corresponding to the optimum recording power; arecording unit recording the optimum recording power and the temperatureinformation in a memory unit; a detecting unit detecting temperatureinformation of an information recording medium; a determining unitdetermining whether the temperature information of the informationrecording medium matches the temperature information recorded in thememory unit; and a setting unit setting an optimum recording power ofthe information recording medium as a recording condition when thetemperature information of the information recording medium matches thetemperature information recorded in the memory unit.

The information recording apparatus of the present invention may furtherinclude: another setting unit estimating another optimum recording powerwhen the temperature information temperature information of theinformation recording medium does not match any temperature informationrecorded in the memory unit, and setting the other optimum recordingpower as the recording condition.

In the information recording apparatus of the present invention, theother optimum recording power is estimated by an approximate calculationor an interpolation calculation with reference to the optimum recordingpower and the temperature information recorded in the memory unit.

In the information recording apparatus of the present invention, therecording unit adds the other optimum recording power to the memory unitin correspondence with the temperature information of the informationrecording medium and identification information of the informationrecording medium.

In the information recording apparatus of the present invention, thememory unit is a memory having a non-volatile characteristic.

Accordingly, with the present invention, even when a light sourcetemperature for recording information in an optical disk is differentcompared to a light source temperature obtained in a previously setrecording condition, an optimum recording condition can be newly setwithout requiring writing in the test-recording area. In addition, sinceno test-recording is required, the time required for recording can beshortened. Furthermore, since recording power is acquired by referringto history information corresponding to each optical disk, a highlyprecise recording condition can be set. Accordingly, recording qualitycan be prevented from degrading, and a satisfactory recording qualitycan be obtained consistently.

Furthermore, even in a case where there is no history informationcorresponding to an optical disk, a highly precise recording power canbe acquired.

Furthermore, with the present invention, precise recording power forrecording information in an optical disk can be maintained.

Furthermore, with the present invention, precision of recording powerbased on the history information can be enhanced by adding historyinformation to the temperature-power table.

Furthermore, since a vast amount of history information is stored in theflash memory, there is a high probability of being able to extract fromthe memory, a light source temperature matching with the detected lightsource temperature, and acquire the optimum recording power precisely.

Other objects and further features of the present invention will beapparent from the following detailed description when read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an optical disk apparatus of the firstembodiment of the present invention;

FIG. 2 is a block diagram for explaining an optical pickup unit in FIG.1;

FIG. 3 is a block diagram of a laser control circuit in FIG. 1;

FIG. 4 shows one example of a temperature-power table stored in a flashmemory;

FIG. 5 is a flow chart for explaining a process of setting recordingconditions according to the first embodiment of the present invention;

FIG. 6 is a diagram for explaining a relation between temperature of alight source and optimum recording power;

FIG. 7 is a flow chart for explaining a process of setting recordingconditions (part 1) according to the second embodiment of the presentinvention; and

FIG. 8 is a flow chart for explaining a process of setting recordingconditions (part 2) according to the second embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, embodiments of the present invention are describedwith reference to the accompanying drawings.

First Embodiment

With reference to FIGS. 1 through 6, an optical disk apparatus of thefirst embodiment is described below.

FIG. 1 is a block diagram showing an optical disk apparatus of the firstembodiment of the present invention.

FIG. 1 shows an optical disk apparatus 20 that includes a spindle motor22 for rotatatively driving an optical disk 15 serving as an informationrecording medium, an optical pickup unit 23, a laser control circuit 24,an encoder 25, a motor driver 27, a reproduction signal processingcircuit 28, a servo controller 33, a buffer RAM 34, a buffer manager 37,an interface 38, a ROM 39, a CPU 40, a RAM 41, a flash memory 43 servingas a memory unit, and a temperature sensor 42 serving as a temperaturedetection unit. It is to be noted that the arrows shown in FIG. 1 merelyindicate the flow of representative signals and information, and are notto be regarded as indicating all the relations among the blocksillustrated in FIG. 1.

The optical pickup unit 23 irradiates a laser light to a spiral orconcentric tracks formed on a recording surface of the optical disk 15and also receives light reflected from the recording surface. Theoptical pickup unit 23 includes, for example, a light source unit 51, acollimator lens 52, a beam splitter 54, an objective lens 60, adetection lens 58, a light receiving unit 59, and a drive system (notshown) that includes a focusing actuator, a tracking actuator, and aseek motor.

The light source unit 51 includes a semiconductor laser (not shown) thatserves as a light source for irradiating a light beam of a prescribedwavelength. A monitor (not shown) detects the light quantity of thelight beam irradiated from the light source unit 51 and sendsirradiation signals indicative of the light quantity of the irradiatedlight to the laser control circuit 24 as feedback. In this embodiment,the irradiated light beam having the greatest intensity is irradiated ina direction referred to as “+X” direction (see FIG. 2). The collimatorlens 52 is disposed on the “+X” side of the light source unit 51 forconverting the irradiated light beam into a substantially parallel light(parallel light rays of the light beam).

The beam splitter 54 is disposed on the “+X” side of the collimator lens52 for separating and guiding a light beam returning from the opticaldisk 15 in the “−Z” direction. The objective lens 60 is disposed on the“+X” side of the beam splitter for forming a light spot on the recordingsurface of the optical disk 15 by condensing a light beam transmittedthrough the beam splitter 54.

The detection lens 58 is disposed on the “−Z” side of the beam splitter54 for condensing a returning (reflected) light beam separated by thebeam splitter 54. The light receiving unit 59 is disposed on the “−Z”side of the detection lens 58. A four part light receiving element of atypical optical disk apparatus is employed as the light receivingelement 59. As in any typical optical pickup unit, the light receivingelement 59 receives light reflected from the recording surface of theoptical disk 15, and outputs signals including, for example, wobbleinformation, reproduction data, focus error information and track errorinformation.

Thus structured, the function of the optical pickup unit 23 is brieflydescribed next. First, the light beam irradiated from the light sourceunit 51 is converted into a substantially parallel light beam andbecomes incident on the beam splitter 54. Then, the light beamtransmitted through the beam splitter 54 is condensed by the objectivelens 60, to thereby form a fine spot on the recording surface of theoptical disk 15. Then, a reflected light returning as a light beam fromthe recording surface of the optical disk 15 is converted as asubstantially parallel light beam by the objective lens 60 and becomesincident on the beam splitter 54. Then, the returning light beam isseparated by the beam splitter 54 and is guided in the “−Z” direction.Then, the light receiving unit 59 receives the returning light beam viathe detection lens 58. The light receiving unit 59 outputs a signal tothe reproduction signal processing circuit 28 according to the receivedquantity of light.

With reference to FIG. 1, the reproduction signal processing unit 28detects, for example, wobble signals, RF signals, and servo signals(focus error signals, tracking error signals) according to the signalsoutput from the optical pickup unit 23. The reproduction signalprocessing unit 28 extracts, for example, address information andsynchronization signals, from the wobble signals. The extracted addressinformation is output to the CPU 40, and the synchronization signals areoutput to the encoder 25. After conducting, for example, an errorcorrection process on the RF signals, the RF signals are stored in thebuffer RAM 34 via the buffer manager 37. Furthermore, the reproductionsignal processing circuit 28 detects asymmetric information andreflectivity information according to the RF signals, and outputs thedetected results to the CPU 40. Meanwhile, it is to be noted that thereproduction signal processing circuit 28 outputs the servo signals tothe servo controller 33.

The servo controller 33 generates a control signal for controlling atracking actuator of the optical pickup unit 23 according to trackingerror signals and outputs the control signal to the motor driver 27. Theservo controller 33 also generates a control signal for controlling afocusing actuator of the optical pickup unit 23 according to focus errorsignals and outputs the control signal to the motor driver 27.

The motor driver 27 controls the tracking actuator and the focusingactuator of the optical pickup unit 23 according to the control signalsfrom the servo controller 33. That is, the motor driver 27 performstracking control and focus control. The motor driver 27 also controlsthe spindle motor 22 and the seek motor of the optical pickup 23according to orders from the CPU 40.

The buffer manager 37 manages output and input data from/to the bufferRAM 34 and serves to inform the CPU 40 when the amount of data stored inthe buffer RAM 34 is a prescribed value.

The encoder 25, in accordance with the orders from the CPU 40, obtainsthe data stored in the buffer RAM 34 via the buffer manager 37, conductsa process, for example, an addition of error correction codes, andgenerates writing signals for writing in the optical disk 15. Then, theencoder 25 synchronizes in accordance with the synchronization signalsfrom the reproduction signal processing circuit 28 and outputs thewriting signals to the laser control circuit 24.

With reference to FIG. 3, the laser control circuit 24 includes, forexample, an LD driver 24 a, a pulse setting circuit 24 b, and a powersetting circuit 24 c. The pulse setting circuit 24 b, in accordance withthe orders from the CPU 40, regulates the starting edge of the writingsignals output from the encoder 25 and changes the pulses thereof. Thepower setting circuit 24 c, in accordance with the orders from the CPU40, sets the recording power for performing a recording procedure. TheLD driver 24 a controls the output of the semiconductor laser from theoptical pickup unit 23 according to the writing signals regulated by thepulse setting circuit 24 b and the recording power set by the powersetting circuit 24 c. The LD driver 24 a controls the output of thesemiconductor laser according to the feedback of the irradiation signalsfrom the monitor (not shown).

With reference to FIG. 1, the interface 38 is a communication interfacethat is interactive with a host such as a personal computer. Theinterface 38 conforms to standard interfaces such as ATAPI (ATAttachment Packet Interface) and SCSI (Small Computer System Interface).

The temperature sensor 42 disposed in the vicinity of the light sourceunit 51 obtains temperature information near the light source unit 51and outputs the obtained information to the CPU 40.

The ROM 39 has programs stored therein written in a code decodable bythe CPU 40 and employed during a process of setting an optimum recordingcondition according to the temperature in the vicinity of the lightsource unit 51 (hereinafter referred to as “first recording conditionsetting program”). It is to be noted that the program stored in the ROM39 is loaded into a main memory of the CPU 40 (not shown) when theoptical disk apparatus 20 is switched on.

The flash memory 43 is stored with a calculation table indicative oftemperature and the results obtained from the temperature sensor 42. TheCPU 40 refers to the calculation table and obtains the temperature inthe vicinity of the light source according to the results obtained fromthe temperature sensor 42 (hereinafter referred to as “light sourcetemperature”). With reference to FIG. 4, the flash memory 43 may store atable, for example, including history information indicative of therelation between light source temperature and recording power incorrespondence to each type of optical disk (hereinafter referred to as“temperature-power table”), which may be used as a database. In thisembodiment, each history includes, for example, three fields which aredisk ID, light source temperature, and optimum recording power. The diskID is identification information provided to each optical disk used forclassification of optical disks. In this embodiment, an eight digitnumber is employed as the disk ID. The flash memory 43 is a non-volatilememory, so that contents stored in the memory will not be erased evenwhen there is no electric power supply.

Next, a process of setting an optimum recording condition (hereinafterreferred to as “recording power setting process”) with the optical diskapparatus 20 will be described with reference to FIG. 5. The flow chartin FIG. 5 corresponds to a set of algorithms performed by the CPU 40.For example, upon receiving a command from a host for conducting arecording procedure, the top address of a program corresponding to theflow chart of FIG. 5 is set to a program counter of the CPU 40, tothereby start the recording power setting process.

First, in step 401, the CPU 40 determines whether the disk ID isrecorded in a prescribed location of the optical disk 15. If thedetermination of the CPU 40 is affirmative, that is, if the disk ID isrecorded in the optical disk 15, the recording power process moves tostep 403.

In step 403, the CPU 40 reads out the disk ID from the prescribedlocation in the optical disk 15 at which the disk ID is recorded. Forexample, in this embodiment, “00000001” is obtained as the disk ID.

In step 405, using the obtained disk ID as a key, the CPU 40 searchesthe temperature-power table stored in the flash memory 43 for obtaininghistory information corresponding to the obtained disk ID.

In step 407, the CPU 40 determines whether there is a historycorresponding to the obtained disk ID in the temperature-power table. Inthis embodiment, the CPU 40 makes an affirmative determination sincehistories corresponding to the obtained disk ID (“00000001”) areincluded in the temperature-power table shown in FIG. 4, therebyproceeding to step 409.

In step 409, the CPU 40 extracts all of the histories corresponding tothe obtained disk ID from the temperature-power table (in thisembodiment, four histories are extracted).

Next, in step 411, the CPU 40 detects a light source temperatureaccording to a signal output from the temperature sensor 42.

Next, in step 413, the CPU 40 sets an effective temperature range. Inthis embodiment, the effective temperature range extends from “minimumvalue of the light source temperature −5° C.” to “maximum value of thelight source temperature+5° C.” (in this embodiment, from (18−5=13° C.)to (40+5=45° C.).

In step 415, the CPU 40 determines whether the obtained light sourcetemperature is included within the effective temperature range. If thedetermination of the CPU 40 is affirmative, that is, if the obtainedlight source temperature is included within the effective temperaturerange, the CPU 40 proceeds to step 417.

In step 417, the CPU 40 obtains a relation between light sourcetemperature and optimum recording power according to the historiesextracted from the temperature-power table. In this embodiment, forexample, the CPU 40 obtains an approximate expression indicating acorrelation between the light source temperature and optimum recordingpower by using a least squares method. In this embodiment, the table inFIG. 4 shows that the optimum recording power is 15 mW when the lightsource temperature is 18° C., the optimum recording power is 17 mW whenthe light source temperature is 25° C., the optimum recording power is20 mW when the light source temperature is 32° C., and the optimumrecording power is 23 mW when the light source temperature is 40° C.Accordingly, the relation between the light source temperature andoptimum recording power may be expressed with an approximate expression(1) described below and shown in FIG. 6.Pw=0.3702×T+8.1068  (1)

Next, in step 419, the CPU 40 applies the detected light sourcetemperature to the approximate expression (1), to thereby obtain theoptimum recording power corresponding to the detected light sourcetemperature. For example, according to the approximate expression (1),the optimum recording power would be 12.92 mW when the detected lightsource temperature is 13° C.

In step 421, the obtained optimum recording power is output to the powersetting circuit 24 c, thereby setting recording power and finishing therecording power setting process.

Meanwhile, in step 401, if there is no disk ID recorded in the opticaldisk 15, the CPU 40 makes a negative determination and proceeds to step431.

In step 431, the CPU 40 creates a new disk ID by providing the diskwith, for example, a random number.

Next, in step 433, the CPU 40 records the newly created disk ID at aprescribed location in the optical disk 15.

Next, in step 435, the CPU 40 adds the newly created disk ID to a newhistory in the temperature-power table.

Next, in step 437, the CPU 40 performs the OPC procedure. That is,prescribed data are test-recorded in the PCA of the optical disk 15 at aprescribed linear speed while recording power is changed in a step bystep manner; then, the data are reproduced successively, and then, ahighest recording quality state, wherein the asymmetric value detectedfrom the reproduced RF signals that relatively matches with a targetvalue obtained by experiments and the like, is determined. Accordingly,the recording power during the highest recording quality state isdefined as the optimum recording power. In addition, reflectivity duringthe highest recording quality state is detected and stored, togetherwith a corresponding disk ID, in the flash memory 43 to be used as thetarget reflectivity.

Next, in step 439, the CPU 40 detects the light source temperatureaccording to output signals from the temperature sensor 42.

In step 441, the CPU 40 records the detected light source temperatureand the optimum recording power obtained by the OPC procedure in thetemperature-power table in correspondence to the disk ID. That is, thedetected light source temperature, the optimum recording power and thedisk ID are added to the history information as a new history. Duringthis procedure, it may be preferable to sort the histories of thehistory information according to, for example, light source temperature,for enabling easier use of the history information. After step 441, theCPU 40 proceeds to step 421.

It is to be noted that if no history corresponding to the disk ID isfound in step 407, the CPU 40 makes a negative determination andproceeds to step 435.

It is also to be noted that if the detected light source temperature isnot included in the effective temperature range (in this embodiment, 13°C. to 45° C.) in step 415, the CPU 40 does not obtain the relationbetween light source temperature and optimum recording power accordingto the histories extracted from the temperature-power table.Accordingly, the CPU 40 makes a negative determination and proceeds tostep 437.

Meanwhile, after the optimum recording power is determined, a recordingprocess is started for allowing data from the host to be recorded in aprescribed recording area of the optical disk 15.

Next, a recording process of the optical disk apparatus 20 is brieflydescribed.

The CPU 40 outputs control signals to the motor driver 27 forcontrolling the rotation of the spindle motor 22 at a prescribedrecording speed. In addition, the CPU 40 also reports the receipt ofrecording commands from the host to the reproduction signal processingcircuit 28. The CPU 40 stores the received data from the host in thebuffer RAM 34 via the buffer manager 37.

When the rotation of the optical disk 15 reaches a prescribed linearspeed, the reproduction signal processing circuit 28 detects trackingerror signals and focus error signals according to the signals outputfrom the light receiving unit 59, and sends the detected signals to theservo controller 33.

In accordance with the tracking error signals, the servo controller 33,using the motor driver 27, drives the tracking actuator of the opticalpickup unit 23 for correcting track deviation. Furthermore, inaccordance with the focus error signals, the servo controller 33, usingthe motor driver 27, drives the focusing actuator of the optical pickupunit 23 for focus correction. In other words, the servo controller 33performs tracking control and focus control.

The reproduction signal processing circuit 28 obtains addressinformation based on the signals output from the optical pickup unit 23,and sends the obtained address information to the CPU 40. Then, inaccordance with the address information, the CPU 40 sends a controlsignal to the motor driver 27, to thereby enable the seek motor of theoptical pickup unit 23 to position the optical pickup unit 23 at aprescribed location for starting a writing procedure.

Then, upon receiving a notice from the buffer manager 37 that the amountof data stored in the buffer RAM 34 has surpassed a prescribed value,the CPU 40 commands the encoder 25 to create writing signals.Furthermore, after the CPU 40 confirms that the optical pickup unit 23is positioned at the prescribed location for starting the writingprocedure, the CPU 40 informs the encoder 25 that the optical pickupunit 23 is in the prescribed location. Accordingly, the encoder 25records the writing signals in the optical disk 15 through use of thelaser control circuit 24 and the optical pickup unit 23.

Next, a reproduction process of the optical disk apparatus 20 is brieflydescribed.

When the CPU 40 receives a command from the host requesting thereproduction process, the CPU 40 outputs control signals to the motordriver 27 for controlling the rotation of the spindle motor 22 at aprescribed reproduction speed. In addition, the CPU 40 also reports thereceipt of reproduction commands from the host to the reproductionsignal processing circuit 28. When the rotation of the optical disk 15reaches a prescribed linear speed, tracking control and focus controlare started. Furthermore, the reproduction signal processing circuit 28detects address information and reports the address information to theCPU 40.

In accordance with the address information, the CPU 40 sends a controlsignal to the motor driver 27, to thereby enable the seek motor of theoptical pickup unit 23 to position the optical pickup unit 23 at aprescribed location for starting a reading procedure. After the CPU 40confirms that the optical pickup unit 23 is positioned at the prescribedlocation for starting the reading procedure, the CPU 40 informs thereproduction signal processing circuit 28 that the optical pickup unit23 is in the prescribed location.

Then, the reproduction signal processing unit 28 detects RF signals fromthe signals output from the light receiving unit 59. After conducting,for example, an error correction process on the RF signals, the RFsignals are stored in the buffer RAM 34. When reproduction data arecompletely stored in the buffer RAM as sector data, the buffer manager37 sends the reproduction data to the host via the interface 38.

It is to be noted that the tracking control and the focus control arecontinued until the reproduction process is completed.

As described above, by employing the CPU 40 and executing the programwith the CPU 40, the optical disk apparatus of this embodiment is ableto provide an identification information obtaining unit, a historyinformation extracting unit, a first determining unit, an identificationinformation recording unit, a temperature range setting unit, a seconddeciding unit, a first setting unit, and a second setting unit. That is,with reference to FIG. 5, step 403 may serve as the identificationinformation obtaining unit, steps 405 to 409 may serve as the historyinformation extracting unit, step 401 may serve as the first determiningunit, step 431 and step 433 may serve as the identification informationrecording unit, step 413 may serve as the temperature range settingunit, step 415 may serve as the second determining unit, steps 417 to421 may serve as the first setting unit, and steps 437 to 441 and step421 may serve as the second setting unit. Nevertheless, the presentinvention is not limited to this embodiment. For example, all of or atleast part of the foregoing steps performed by the CPU 40 using theprogram may be provided in the form of hardware.

In this embodiment, among the programs stored in the ROM 39, the programserving to perform the steps shown in the flow chart in FIG. 5 signifiesthe first recording condition setting program.

With reference to FIG. 5, step 403 is included in step a) described inclaim 1, steps 405 through 409 are included in steps b) and c) describedin claim 1, step 411 is included in step d) described in claim 1, andsteps 417 through 421 are included in steps e) and f) described in claim1. Furthermore, step 401 is included in step g) described in claim 2,and steps 431 and 433 are included in steps h) and i) described in claim2. Furthermore, step 413 is included in step j) described in claim 5,step 415 is included in step k) described in claim 5, and steps 437, 439and 421 are included in steps l) and m) described in claim 5.Furthermore, step 441 is included in step n) described in claim 6.

Accordingly, as described above, the optical disk apparatus and therecording condition setting method of this first embodiment are able toset a recording condition in which the recording power is acquired byobtaining a disk ID, then searching through a temperature-power tableaccording to the disk ID, then extracting history informationcorresponding to the disk ID according to the search, then detecting alight source temperature, and then relating the detected light sourcetemperature with the obtained history information. Therefore, even whena light source temperature for recording information in an optical diskis different compared to a light source temperature obtained in apreviously set recording condition, an optimum recording condition canbe newly set without requiring the use of a test-recording area. Inaddition, since no test-recording is required, the time required forrecording can be shortened. Furthermore, since recording power isacquired by referring to history information corresponding to each typeof optical disk, a highly precise recording condition can be set.Accordingly, recording quality can be prevented from degrading, and asatisfactory recording quality can be obtained consistently.

Furthermore, with the first embodiment, an approximate expressionindicative of a relation between light source temperature and optimumrecording power can be obtained, in accordance with histories extractedfrom a temperature-power table, by using a least squares method. Then, adetected light source temperature is applied to the approximateexpression, to thereby acquire an optimum recording power correspondingto the detected light source temperature. Therefore, even in a casewhere there is no history information corresponding to an optical disk,a highly precise recording power can be acquired.

Furthermore, with the first embodiment, prior to acquiring an optimumrecording power, an effective temperature range is set according toextracted history information. Then, whether or not a detected lightsource temperature is included within the effective temperature range isdetermined. If it is determined that the detected light sourcetemperature is not included within the effective temperature range, anOPC procedure is performed to thereby acquire an optimum recording powerand set the acquired optimum recording power as a recording poweremployed for recording information in an optical disk. Accordingly, aprecise recording power for recording information in an optical disk canbe maintained. Therefore, recording quality can be prevented fromdegrading, and a satisfactory recording quality can be obtainedconsistently.

Furthermore, with the first embodiment, in a case where an OPC procedureis performed, history information indicative of a relation between anoptimum recording power obtained from the OPC procedure, a detectedlight source temperature, and a disk ID is added to thetemperature-power table. By adding history information to thetemperature-power table, precision of recording power based on thehistory information can be enhanced.

Furthermore, with the optical disk apparatus of the first embodiment,recording can be performed steadily with excellent recording qualitysince an optimum recording power corresponding to light sourcetemperature is obtained when setting a recording condition.

Although each history in the temperature-power table of the firstembodiment is formed of three fields (disk ID, light source temperature,and optimum recording power), it is to be noted that other fields (e.g.date when data were obtained, recording speed) may also be added to eachhistory.

Although a single temperature-power table is employed in the firstembodiment, more tables may be employed, for example, temperature-powertables corresponding to each optical disk manufacturer or supplier, inwhich each of the tables is formed of three fields including disk ID,light source temperature, and optimum recording power. This enableshistory information to be searched more easily.

Although the first embodiment employs eight digit numbers as the diskIDs, the numbers are not to be limited to eight digits. Moreover,alphabet letters, symbols, or numerals, for example, may be employedindependently or in combination with each other.

Although the first embodiment employs disk ID as identificationinformation for identifying an optical disk, manufacturer information,for example, may also be employed.

Although the first embodiment approximates a relation between lightsource temperature and optimum recording power with use of a linearexpression, a polynomial expression may also be used. Furthermore, aninterpolation expression may be used instead of an approximateexpression. In other words, the expression used for obtaining an optimumrecording power corresponding to a detected light source temperature isnot to be limited in particular, as long as the optimum recording powercan be obtained precisely.

Furthermore, with the first embodiment, a relation between a lightsource temperature and an optimum recording power is obtained whenever arecording condition is to be set. It is, however, not requisite toobtain the relation whenever the recording condition is to be set. Forexample, a relation between a light source temperature and an optimumrecording power may be obtained beforehand upon obtaining new historyinformation and a recording condition may be set in accordance with therelation obtained beforehand. Thereby, processing time can be saved.

Although the first embodiment records the first recording conditionsetting program in the ROM 39, the program may be recorded in otherrecording media (e.g. CD-ROM, optic-magneto disk, flash memory, flexibledisk). In this case, a drive apparatus corresponding to each recordingmedium may be provided for allowing the program to be installed from therespective drive apparatus. In other words, it is not required to recordthe first recording condition setting program in the ROM 39, as long asthe program is loaded in the main memory of the CPU 40 for execution.

It is to be noted that, for example, the process for obtaining the diskID may be omitted in a case where the type of optical disk is limited.This case is described in the second embodiment given below.

Second Embodiment

A second embodiment of the present invention is next described withreference to FIGS. 7 and 8.

The second embodiment has a feature of employing a method for setting anoptimum recording condition which is different from that of the firstembodiment. Other components (e.g. optical pickup unit, optical diskapparatus) are the same as the first embodiment. Therefore, mainly thedifferences between the second embodiment and the first embodiment arehereinafter described. Furthermore, like components of the second andfirst embodiments are denoted by like numerals and are not furtherdescribed. Furthermore, the second embodiment is provided under the sameconditions as those of the first embodiment.

ROM 39 has stored a second recording condition setting program insteadof the first recording condition setting program.

A process for setting recording power is next described with referenceto FIG. 7. The flow chart in FIG. 7 corresponds to a set of algorithmsperformed by the CPU 40.

First, in step 501, the CPU 40 detects light source temperatureaccording to a signal output from the temperature sensor 42.

In step 503, using the detected light source temperature as a key, theCPU 40 searches the temperature-power table stored in the flash memory43 and determines whether a history with a light source temperature thesame as that of the detected light source temperature exists. If thehistory exists, the CPU 40 makes an affirmative determination, andproceeds to step 505.

In step 505, the CPU 40 extracts all of the histories having lightsource temperatures that are the same as the detected light sourcetemperature.

In step 507, the CPU 40 acquires an optimum recording power from theextracted histories.

In step 509, the CPU 40 outputs the acquired optimum recording power tothe power setting circuit 24 c. After the acquired optimum recordingpower is output to the power setting circuit 24 c, the recording powersetting process is finished.

Meanwhile, in step 503, if there is no history with a light sourcetemperature that is the same as the detected light source temperature,the CPU 40 makes a negative determination and proceeds to step 521.

In step 521, an approximate expression indicating a relation betweenlight source temperature and optimum recording power is obtained, inaccordance with history information recorded in the temperature-powertable, by using, for example, a least squares method. It is to be notedthat an interpolation expression, for example, may be used instead ofthe approximate expression. In other words, as long as an optimumrecording power corresponding to the detected light source temperaturecan be obtained precisely, the expression used is not particularlylimited.

In step 523, the CPU 40 applies the detected light source temperature tothe approximate expression, to thereby acquire the optimum recordingpower corresponding to the detected light source temperature. Then, theCPU 40 proceeds to step 509.

After the optimum recording power is acquired, a process of recordingdata from the host to a prescribed recording area of the optical disk 15is performed. Along with this recording process, a recording powercorrection process is also performed. The recording power correctionprocess is next described with reference to FIG. 8. The flow chart inFIG. 8 corresponds to a set of algorithms performed by the CPU 40. Uponstarting the recording process, the top address of a programcorresponding to the flow chart of FIG. 8 is set to a program counter ofthe CPU 40, to thereby start the recording power correction process. Itis to be noted that a target reflectivity detected beforehand during anOPC procedure is stored in the flash memory 43.

First, in step 601, the CPU 40 determines whether the recording of datais finished. When the CPU 40 determines that the recording of data isnot finished, the CPU 40 makes a negative determination and proceeds tostep 603.

In step 603, the CPU 40, using the reproduction signal processingcircuit 28, detects reflectivity of an area of the optical disk 15 inwhich data are recorded.

In step 605, the CPU 40 determines whether correction of recording poweris required by comparing the detected reflectivity and the targetreflectivity already stored in the flash memory 43. In this case, whenthe difference between the detected reflectivity and the targetreflectivity is greater than a prescribed value, the CPU 40 determinesthat this result requires correction of recording power, concludes thisresult as affirmative, and proceeds to step 607.

In step 607, the CPU 40 corrects the recording power so as to match thedetected reflectivity with the target reflectivity and outputs thecorrected recording power to the power setting circuit 24 c. It is to benoted that a relation between the said difference and the degree ofcorrecting the recording power is obtained beforehand throughexperiments and the like, and that the obtained relation is stored inthe flash memory 43.

In step 609, a light source temperature is detected according to asignal output from the temperature sensor 42.

Next, in step 611, the detected light source temperature, the correctedrecording power and disk ID are added to the temperature-power table.After the detected light source temperature, the corrected recordingpower and disk ID are added to the temperature-power table, the CPU 40returns to step 601. By adding the detected light source temperature,the corrected recording power and disk ID to the temperature-powertable, the amount of history information is increased. It is to be notedthat the detected reflectivity may also be added to the historyinformation.

Meanwhile, when the difference between the detected reflectivity and thetarget reflectivity is no more than the prescribed value, the CPU 40determines that this result requires no correction of recording power,concludes this result as negative, and returns to step 601.

Furthermore, when the CPU 40 determines that the recording of data isfinished, the CPU 40 concludes this result as affirmative and finishesthe recording power correction process.

As described above, by employing the CPU 40 and executing the secondcondition setting program in the CPU 40, the optical disk apparatus ofthe second embodiment is able to provide a history acquiring unit, ahistory recording unit, a determining unit, a first recording powersetting unit, and a second recording power setting unit. That is, withreference to FIGS. 7 and 8, steps 603, 607 and 609 may serve as thehistory acquiring unit, step 611 may serve as the history recordingunit, steps 501 and 503 may serve as the determining unit, steps 505,507 and 509 may serve as the first recording power setting unit, andsteps 521, 523 and 509 may serve as the second recording power settingunit. Thus structured, a recording process and a reproduction processmay be performed in the same manner as in the first embodiment.

In the second embodiment, among the programs stored in the ROM 39, theprogram serving to perform the steps shown in the flow charts in FIGS. 7and 8 signifies the second recording condition setting program.

With reference to FIGS. 7 and 8, steps 603, 607 and 609 are included instep a) described in claim 7, step 611 is included in step b) describedin claim 7, steps 501 and 503 are included in steps c) and d) describedin claim 7, and steps 505, 507 and 509 are included in step e) describedin claim 7. Furthermore, steps 521, 523, and 509 are included in stepsf) and g) described in claim 8.

Accordingly, as described above, the optical disk apparatus and therecording condition setting method of the second embodiment are alsoable to set a recording condition by acquiring an optimum recordingpower corresponding to a detected light source temperature. In thesecond embodiment, first, a flash memory including history informationindicative of optimum recording power and a light source temperaturecorresponding to the optimum recording power is prepared, in which theoptimum recording power and the corresponding light source temperatureare stored in the flash memory as history information whenever arecording process is performed. The optimum recording power in this caseis obtained by referring to received light reflected from an opticaldisk during the recording process. Under this condition, beforebeginning the recording process, a light source temperature is newlydetected and is compared with previously detected light sourcetemperatures stored in the flash memory. When the newly detected lightsource temperature matches with any of the previously detected lightsource temperatures stored in the flash memory, an optimum recordingpower corresponding to the newly detected light source temperature canbe extracted from the flash memory. Therefore, even when a light sourcetemperature detected before a recording process is different compared toa light source temperature obtained from a previously set recordingcondition, an optimum recording condition can be newly set withouthaving to use a test-recording area. In addition, since notest-recording is required, the time required for starting a recordingprocess can be shortened. Since a vast amount of history information isstored in the flash memory, there is a high probability of being able toextract from the flash memory a light source temperature matching withthe detected light source temperature. Accordingly, recording qualitycan be prevented from degrading, and a satisfactory recording qualitycan be obtained consistently.

Furthermore, with the second embodiment, even in a case where a newlydetected light source temperature does not match with any of thepreviously detected light source temperatures stored in the flashmemory, an optimum recording power corresponding to the newly detectedlight source temperature can be estimated and set as a new recordingcondition by referring to the combinations of the light sourcetemperatures and the optimum recording powers stored in the flashmemory. Therefore, even in a case where there is no history informationcorresponding to a newly detected light source temperature, a highlyprecise recording power can be acquired.

Furthermore, since the second embodiment stores optimum recording power,light source temperature, and disk ID in a flash memory, no OPCprocedure is required to be repeatedly performed in a case, for example,where an optical disk apparatus is switched on after being switched off,or where an optical disk is re-inserted into an optical disk apparatusafter being withdrawn therefrom. Thereby, the area for test-recordingcan be saved.

Furthermore, with the optical disk apparatus of the second embodiment,recording can be performed steadily with excellent recording qualitysince an optimum recording power corresponding to light sourcetemperature is obtained when setting a recording condition.

Furthermore, with the second embodiment, a relation between a lightsource temperature and an optimum recording power is obtained whenever anewly detected light source temperature does not match with thepreviously detected light source temperatures stored in the flashmemory. It is, however, not required to obtain the relation whenever anewly detected light source temperature does not match with thepreviously detected light source temperatures stored in the flashmemory. For example, a relation between a light source temperature andan optimum recording power may be obtained beforehand, upon obtainingnew history information, and a recording condition may be set inaccordance with the relation obtained beforehand. Thereby, process timecan be saved.

Furthermore, although an optimum recording power according to reflectedlight from an optical disk during a recording process and a light sourcetemperature detected during the recording process are stored in theflash memory in the second embodiment, an optimum recording powerobtained from an OPC procedure, and a light source temperature duringthe OPC procedure may also be stored in the flash memory as historyinformation. Accordingly, history information can be enhanced forattaining a more precise recording condition.

Although the second embodiment records the second recording conditionsetting program in the ROM 39, the program may be recorded in otherrecording media (e.g. CD-ROM, optic-magneto disk, flash memory, flexibledisk). In this case, a drive apparatus corresponding to each recordingmedium may be provided for allowing the program to be installed from therespective drive apparatus. In other words, it is not required to recordthe second recording condition setting program in the ROM 39, as long asthe program is loaded to the main memory of the CPU 40 for execution.

Although recording power is employed as a recording condition in theabove-described embodiments, it is to be noted that the recordingcondition of the present invention is not to be limited to recordingpower. For example, the shape of a pulse may be employed as therecording condition of the present invention.

Although a flash memory is employed as a memory unit in theabove-described embodiments, an EEPROM, for example, may also be used.That is, any memory unit may be employed as long as the memory unit hasa non-volatile characteristic.

Although an optical disk apparatus capable of recording and reproducinginformation is employed in the above-described embodiments, an opticaldisk apparatus able to perform at least one function among a recordingfunction, a reproduction function, and an erasing function may beemployed.

Although a single light source is employed in the above-describedembodiments, plural light sources may also be employed. For example, twolight sources comprising a light source emitting a light beam with awavelength of 650 nm and a light source emitting a light beam with awavelength of 780 nm may be employed.

As described above, with the recording condition setting method of thepresent invention, recording quality can be prevented from degrading,and a satisfactory recording quality can be obtained consistently.

Furthermore, with the program and recording medium of the presentinvention, a computer using the program and recording medium forcontrolling an information recording apparatus can prevent recordingquality from degrading, and obtain a satisfactory recording qualityconsistently.

Furthermore, with the information recording apparatus of the presentinvention, an excellent recording quality can be obtained consistently.

Further, the present invention is not limited to these embodiments, butvarious variations and modifications may be made without departing fromthe scope of the present invention.

The present application is based on Japanese Priority Application No.2002-243456 filed on Aug. 23, 2002, with the Japanese Patent Office, theentire contents of which are hereby incorporated by reference.

1. A recording condition setting method, comprising the steps of: a)obtaining identification information from an information recordingmedium; b) searching through a table including a plurality of historyinformation corresponding to the identification information of theinformation recording medium, wherein the history information comprises:temperature information detected in the vicinity of a light source andcorresponding optimum recording power, that are together stored in thetable during an OPC (Optimum Power Control) procedure; and temperatureinformation detected in the vicinity of a light source and correspondingoptimum recording power according to reflected light from an opticaldisk during a recording process, that are together stored in the table;c) extracting history information corresponding to the identificationinformation; d) detecting temperature information detected in thevicinity of the light source; e) acquiring an optimum recording power byreferring to the temperature information detected in step d) and thehistory information extracted in step c); and f) setting the optimumrecording power acquired in step e) as a recording condition.
 2. Therecording condition setting method as claimed in claim 1, furthercomprising the steps of: g) determining whether the identificationinformation is recorded in the information recording medium; h) creatingnew identification information when the identification information isnot recorded in the information recording medium; and i) recording thenew identification information in the information recording medium. 3.The recording condition setting method as claimed in claim 1, whereinstep e) further comprises: obtaining a predetermined expressionindicative of a relation between temperature information and optimumrecording power with reference to the history information extracted instep c); and applying the temperature information detected in step d) tothe obtained the predetermined expression.
 4. The recording conditionsetting method as claimed in claim 3, wherein the predeterminedexpression is an approximate expression or an interpolation expression.5. The recording condition setting method as claimed in claim 1, furthercomprising the steps of: j) setting an effective temperature rangeaccording to the history information extracted in step c); k)determining whether the temperature information detected in step d) isincluded in the effective temperature range; l) acquiring anotheroptimum recording power by test-recording in the information recordingmedium when the temperature information detected in step d) is notincluded in the effective temperature range; and m) setting the otheroptimum recording power as the recording condition.
 6. The recordingcondition setting method as claimed in claim 5, further comprising astep of: n) adding the other optimum recording power to the table incorrespondence with the temperature information detected in step d) andthe identification information.
 7. A recording condition setting method,comprising the steps of: obtaining identification information from aninformation recording medium; a) acquiring an optimum recording powerfor the information recording medium and temperature informationcorresponding to the optimum recording power, wherein the optimumrecording power is acquired from history information, and wherein thehistory information comprises: temperature information detected in thevicinity of a light source and corresponding optimum recording power,that are together stored in a table during an OPC (Optimum PowerControl) procedure; and temperature information detected in the vicinityof a light source and corresponding optimum recording power according toreflected light from an optical disk during a recording process, thatare together stored in the table; b) recording the optimum recordingpower and the temperature information in a memory; c) detectingtemperature information of the information recording medium; d)determining whether the temperature information of the informationrecording medium matches the temperature information recorded in thememory; and e) setting an optimum recording power of the informationrecording medium as a recording condition when the temperatureinformation of the information recording medium matches the temperatureinformation recorded in the memory.
 8. The recording condition settingmethod as claimed in claim 7, further comprising the steps of: f)estimating another optimum recording power when the temperatureinformation of the information recording medium does not match with anytemperature information recorded in the memory; and g) setting the otheroptimum recording power as the recording condition.
 9. The recordingcondition setting method as claimed in claim 8, wherein the otheroptimum recording power in step f) is estimated by an approximateexpression or an interpolation expression with reference to the optimumrecording power and the temperature information recorded in the memory.10. The recording condition setting method as claimed in claim 8,further comprising a step of: h) adding the other optimum recordingpower to the memory in correspondence with the temperature informationof the information recording medium and identification information ofthe information recording medium.
 11. A recording medium comprising aprogram having instructions for causing a computer to implement a methodcomprising the steps of: a) obtaining identification information from aninformation recording medium; b) searching through a table including aplurality of history information corresponding to the identificationinformation of the information recording medium, the history informationcomprising: temperature information detected in the vicinity of a lightsource and corresponding optimum recording power, that are togetherstored in the table during an OPC (Optimum Power Control) procedure; andtemperature information detected in the vicinity of a light source andcorresponding optimum recording power according to reflected light froman optical disk during a recording process, that are together stored inthe table; c) extracting history information corresponding to theidentification information; d) detecting temperature informationdetected in the vicinity of the light source; e) acquiring an optimumrecording power by referring to the temperature information detected instep d) and the history information extracted in step c); and f) settingthe optimum recording power acquired in step e) as a recordingcondition.
 12. The recording medium as claimed in claim 11, wherein theinstructions for causing a computer to implement a method furthercomprising the steps of: g) determining whether the identificationinformation is recorded in the information recording medium; h) creatingnew identification information when the identification information isnot recorded in the information recording medium; and i) recording thenew identification information in the information recording medium. 13.The recording medium as claimed in claim 11, wherein step e) furthercomprises: obtaining a predetermined expression indicative of a relationbetween temperature information and optimum recording power withreference to the history information extracted in step c); and applyingthe temperature information detected in step d) to the obtained thepredetermined expression.
 14. The recording medium as claimed in claim13, wherein the predetermined expression is an approximate expression oran interpolation expression.
 15. The recording medium as claimed inclaim 11, wherein the instructions for causing a computer to implement amethod further comprising the steps of: j) setting an effectivetemperature range according to the history information extracted in stepc); k) determining whether the temperature information detected in stepd) is included in the effective temperature range; l) acquiring anotheroptimum recording power by test-recording in the information recordingmedium when the temperature information detected in step d) is notincluded in the effective temperature range; and m) setting the otheroptimum recording power as the recording condition.
 16. The recordingmedium as claimed in claim 15, wherein the instructions for causing acomputer to implement a method further comprising a step of: n) addingthe other optimum recording power to the table in correspondence withthe temperature information detected in step d) and the identificationinformation.
 17. A recording medium comprising a program havinginstructions for causing a computer to implement a method comprising thesteps of: obtaining manufacturer information from an informationrecording medium; a) acquiring an optimum recording power for theinformation recording medium and temperature information correspondingto the optimum recording power; b) recording the optimum recording powerand the temperature information in a memory; c) detecting temperatureinformation of the information recording medium, the temperatureinformation comprising: temperature information corresponding to anoptimum recording power detected in the vicinity of a light sourceduring an OPC (Optimum Power Control) procedure; and temperatureinformation detected in the vicinity of a light source, the temperatureinformation corresponding to an optimum recording power according toreflected light from an optical disk during a recording process; d)determining whether the temperature information of the informationrecording medium matches the temperature information recorded in thememory; and e) setting an optimum recording power of the informationrecording medium as a recording condition when the temperatureinformation of the information recording medium matches the temperatureinformation recorded in the memory.
 18. The recording medium as claimedin claim 17, wherein the instructions for causing a computer toimplement a method further comprising the steps of: f) estimatinganother optimum recording power when the temperature information of theinformation recording medium does not match with any temperatureinformation recorded in the memory; and g) setting the other optimumrecording power as the recording condition.
 19. The recording medium asclaimed in claim 18, wherein the other optimum recording power in stepf) is estimated by an approximate calculation or an interpolationcalculation with reference to the optimum recording power and thetemperature information recorded in the memory.
 20. The recording mediumas claimed in claim 18, wherein the instructions for causing a computerto implement a method further comprising a step of: h) adding the otheroptimum recording power to the memory in correspondence with thetemperature information of the information recording medium andmanufacturer information of the information recording medium.
 21. Arecording medium having a program having instructions for causing acomputer to implement a method recorded thereto, the program comprisingthe steps of: a) obtaining identification information from aninformation recording medium; b) searching through a table including aplurality of history information corresponding to the identificationinformation of the information recording medium, each historyinformation including temperature information detected in the vicinityof a light source, corresponding optimum recording power, and recordingspeed; c) extracting history information corresponding to theidentification information, the history information comprising:temperature information detected in the vicinity of a light source andcorresponding optimum recording power, that are together stored in atable during an OPC (Optimum Power Control) procedure; and temperatureinformation detected in the vicinity of a light source and correspondingoptimum recording power according to reflected light from an opticaldisk during a recording process, that are together stored in the table;d) detecting temperature information detected in the vicinity of thelight source; e) acquiring an optimum recording power by referring tothe temperature information detected in step d) and the historyinformation extracted in step c); and f) setting the optimum recordingpower acquired in step e) as a recording condition.
 22. The recordingmedium as claimed in claim 21, wherein the instructions for causing acomputer to implement a method further comprises the steps of: g)determining whether the identification information is recorded in theinformation recording medium; h) creating new identification informationwhen the identification information is not recorded in the informationrecording medium; and i) recording the new identification information inthe information recording medium.
 23. The recording medium as claimed inclaim 21, wherein step e) further comprises: obtaining a predeterminedexpression indicative of a relation between temperature information andoptimum recording power with reference to the history informationextracted in step c); and applying the temperature information detectedin step d) to the obtained the predetermined expression.
 24. Therecording medium as claimed in claim 21, wherein the predeterminedexpression is an approximate expression or an interpolation expression.25. The recording medium as claimed in claim 21, wherein theinstructions for causing a computer to implement a method furthercomprises the steps of: j) setting an effective temperature rangeaccording to the history information extracted in step c); k)determining whether the temperature information detected in step d) isincluded in the effective temperature range; l) acquiring anotheroptimum recording power by test-recording in the information recordingmedium when the temperature information detected in step d) is notincluded in the effective temperature range; and m) setting the otheroptimum recording power as the recording condition.
 26. The recordingmedium as claimed in claim 21, wherein the instructions for causing acomputer to implement a method further comprises the step of: n) addingthe other optimum recording power to the table in correspondence withthe temperature information detected in step d) the identificationinformation, and the recording speed.
 27. A recording medium having aprogram recorded thereto, the program having instructions for causing acomputer to implement a method comprising the steps of: obtainingidentification information from an information recording medium; a)acquiring an optimum recording power for the information recordingmedium and temperature information corresponding to the optimumrecording power, wherein the optimum recording power is acquired fromhistory information, and wherein the history information comprises:temperature information detected in the vicinity of a light source andcorresponding optimum recording power, that are together stored in atable during an OPC (Optimum Power Control) procedure; and temperatureinformation detected in the vicinity of a light source and correspondingoptimum recording power according to reflected light from an opticaldisk during a recording process, that are together stored in the table;b) recording the optimum recording power and the temperature informationin a memory; c) detecting temperature information of the informationrecording medium; d) determining whether the temperature information ofthe information recording medium matches the temperature informationrecorded in the memory; and e) setting an optimum recording power of theinformation recording medium as a recording condition when thetemperature information of the information recording medium matches thetemperature information recorded in the memory.
 28. The recording mediumas claimed in claim 27, wherein the instructions for causing a computerto implement a method further comprises the steps of: f) estimatinganother optimum recording power when the temperature information of theinformation recording medium does not match with any temperatureinformation recorded in the memory; and g) setting the other optimumrecording power as the recording condition.
 29. The recording medium asclaimed in claim 28, wherein the other optimum recording power in stepf) is estimated by an approximate calculation or an interpolationcalculation with reference to the optimum recording power and thetemperature information recorded in the memory.
 30. The recording mediumas claimed in claim 28, wherein the instructions for causing a computerto implement a method further comprises a step of: h) adding the otheroptimum recording power to the memory in correspondence with thetemperature information of the information recording medium andidentification information of the information recording medium.
 31. Aninformation recording apparatus comprising: a memory unit storing atable including a plurality of history information corresponding to theidentification information of the information recording medium, thehistory information comprising: temperature information detected in thevicinity of a light source and corresponding optimum recording power,that are together stored in the table during an OPC (Optimum PowerControl) procedure; and temperature information detected in the vicinityof a light source and corresponding optimum recording power according toreflected light from an optical disk during a recording process, thatare together stored in the table; a detecting unit detecting temperatureinformation detected in the vicinity of the light source; an obtainingunit obtaining identification information from an information recordingmedium; an extracting unit extracting history information correspondingto the identification information by searching through the table; asetting unit acquiring an optimum recording power by referring to thetemperature information detected by the detecting unit and the historyinformation extracted by the extracting unit, and setting the acquiredoptimum recording power as a recording condition; and a recording unitrecording information in the information recording medium according tothe recording condition.
 32. The information recording apparatus asclaimed in claim 31, further comprising: a determining unit determiningwhether the identification information is recorded in the informationrecording medium; and an identification information recording unitcreating new identification information when the identificationinformation is not recorded in the information recording medium, andrecording the new identification information in the informationrecording medium.
 33. The information recording apparatus as claimed inclaim 31, wherein the setting unit acquires the optimum recording powerby: obtaining a predetermined expression indicative of a relationbetween temperature information and optimum recording power withreference to the history information extracted by the extracting unit;and applying the detected temperature information to the obtained thepredetermined expression.
 34. The information recording apparatus asclaimed in claim 33, wherein the predetermined expression is anapproximate expression or an interpolation expression.
 35. Theinformation recording apparatus as claimed in claim 32, furthercomprising: a temperature range setting unit setting an effectivetemperature range according to the history information extracted by theextracting unit; another determining unit determining whether thetemperature information detected by the detecting unit is included inthe effective temperature range; and another setting unit acquiringanother optimum recording power by test-recording in the informationrecording medium when the temperature information detected by thedetecting unit is not included in the effective temperature range, andsetting the other optimum recording power as the recording condition.36. The information recording apparatus as claimed in claim 35, whereinthe other setting unit adds the other optimum recording power to thetable in correspondence with the temperature information detected by thedetecting unit and the identification information.
 37. The informationrecording apparatus as claimed in claim 31, wherein the memory unit is amemory having a non-volatile characteristic.
 38. An informationrecording apparatus comprising: an acquiring unit acquiringidentification information from an information recording medium, anoptimum recording power for the information recording medium, andtemperature information corresponding to the optimum recording power,wherein the acquiring unit searches through history information thatcomprises: temperature information detected in the vicinity of a lightsource and corresponding optimum recording power, that are togetherstored in a table during an OPC (Optimum Power Control) procedure; andtemperature information detected in the vicinity of a light source andcorresponding optimum recording power according to reflected light froman optical disk during a recording process, that are together stored inthe table; a recording unit recording the optimum recording power andthe temperature information in a memory unit; a detecting unit detectingtemperature information of the information recording medium; adetermining unit determining whether the temperature information of theinformation recording medium matches the temperature informationrecorded in the memory unit; and a setting unit setting an optimumrecording power of the information recording medium as a recordingcondition when the temperature information of the information recordingmedium matches the temperature information recorded in the memory unit.39. The information recording apparatus as claimed in claim 38, furthercomprising another setting unit estimating another optimum recordingpower when the temperature information temperature information of theinformation recording medium does not match any temperature informationrecorded in the memory unit, and setting the other optimum recordingpower as the recording condition.
 40. The information recordingapparatus as claimed in claim 39, wherein the other optimum recordingpower is estimated by an approximate calculation or an interpolationcalculation with reference to the optimum recording power and thetemperature information recorded in the memory unit.
 41. The informationrecording apparatus as claimed in claim 39, wherein the recording unitadds the other optimum recording power to the memory unit incorrespondence with the temperature information of the informationrecording medium and identification information of the informationrecording medium.
 42. The information recording apparatus as claimed inclaim 38, wherein the memory unit is a memory having a non-volatilecharacteristic.